A fuel cell is an electrochemical conversion device that produces electricity by oxidizing a fuel. A fuel cell typically includes an anode, a cathode, and an electrolyte between the anode and the cathode. A fuel cell system usually includes multiple fuel cells electrically connected to one another in series via interconnects (sometimes collectively referred to as a “fuel cell unit”) and several components configured to provide the fuel to the anodes of the fuel cells and an oxidant to the cathodes of the fuel cells. The oxygen in the oxidant is reduced at the cathode into oxygen ions that diffuse through the electrolytes into the anodes. The fuel is oxidized at the anodes, which produces electrons that flow through an electrical load.
Solid oxide fuel cell (SOFC) systems (and other high-temperature fuel cell systems) require a relatively high operating temperature, such as 1000 degrees Celsius, to maintain low internal electrical resistance and achieve optimal performance. Accordingly, there is a need for systems and methods for controlling high-temperature fuel cell systems to maintain a desired temperature in the fuel cell stack.